Sound-box.



J. A. STEURER.

SOUND BOX.

APPLICATION FILED Nov, I8. 1915.

Patented July 25, 1916.

A TTOR NE YS UNITED sTAT s PATENT OFFICE.

JOHN A. STEURER, OF NEW YORK, N. Y.

SOUND-BOX.

Application filed November 18, 1915.

To all whom it may concern:

Be it known that I, JOHN A. STEURER, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Sound-Boxes; and Ido hereby declare the following to be a full, clear, and exactdescription of the in vention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention consists in the novel features hereinafter describedreference being had to the accompanying drawing in which is shown oneembodiment of my invention selected by me for purposes of illustrationtogether with several slight modifications of the same, and saidinvention is fully disclosed in the following description and claims.

In the use of the reproducing devices or sound boxes of talking machinestwo objectionable features stand out prominently. One is the metallicresonance which is usu ally produced in a greater or lesser extent inpractically all sound boxes, and another is the mufl'ling of certainsounds which I attribute to the interference with the vibration of thediaphragm at and adjacent to the point of connection between the stylusarm and the diaphragm, that is to say at its central portion. Thislatter mufl'ling or damping of the tone at the center of the diaphragmis also observed in the use of practically all forms of sound boxes withwhich I am familiar, and produces a muddiness or lack of clarity of tonewhich seriously mars the perfection of reproduction and is perhapsespecially noticeable in reproducing from records of the human voiceand'of the concerted instrumental selections.

According to my invention I employ a non-metallic diaphragm, preferablyof mica, and I adhesively secure to one face of the diaphragm a disk ofthin sheet material which is non-absorbent, waterproof, unaffected byheat or cold, and which will therefore never warp or crack, andpreferably of material which combines the qualities of a solidquasi-vitreous base with those of a fibrous material. The specificmaterial, which as a result of many experiments I have found to give thebest results, is what is known in the trade as bakelite dilecto which isa composite body comprising sheets of paper impregnated with bakelite orcom- Specification of Letters Patent.

Patented July 25, 1916.

Serial No. 62,126.

ing a greater or lesser distance toward the extreme marginal portions ofthe diaphragm. I have found in practice that the size of the disk may bevaried from a disk of comparatively small diameter to a disk ofsubstantially the same diameter as the diaphragm according to theparticular amplifying devices of the phondgraph or other talking machinewith which the sound box is used. The effect of this disk is to clarifythe tone produced by the diaphragm eliminating substantially allmetallic resonance and also eliminating the muliled effect usuallyproduced in talking machines, render.- ing with perfect clarity both thetones and over-tones of the human voice and the vari ous musicalinstruments whether used separately or in concerted music. I have alsofound that in connection with the non-metallie diaphragm provided withthe described clarifying disk the beneficial results are obtained morecertainly and to a more perfect degree by employing the diskinconnection with a sound box having a non-metallic body and in which thesupports for the stylus arm are connected directly to the nonmetallicbody instead of to any metallic portion of the sound box, and in thepreferred form of my invention herein illustrated and described I formthe body of the sound box also of bakelite dilecto, thus not onlyeliminating still further the tendency to metallic resonance butproviding a support for the diaphragm, and stylus arm having similarcharacteristics to those of the clarifying disk, and cooperatingtherewith in producing pure tones and over-tones.

In the accompanying drawings: Figure 1 represents a front elevation of asound box or reproducing device constructed accord ing to and embodyingmy invention. Fig. 2 is a vertical sectional view of the same.

Figs. 3 and l are detail yiews of a portion of the device showingslightly modified arrangements for mounting the stylus arm. Fig. 5 is amagnified partial section of the diaphragm and disk.

Referring to the drawings, 1 represents the body of the sound box whichis of the usual form and is preferably formed of nonmetallic material,preferably a combination of quasi-vitreous material and fibrousmaterial. and for this purpose I prefer to employ bakelite dileeto whichis turned from a solid block so as to provide the rear wall, 2, thediaphragm recess and av recess, a, of larger diameter to receive thediaphragm retaining ring, 5, which is also preferably made of the samematerial. All the parts of the sound box which are formed of bake litedilecto ha we the strata of fibrous material extending in planesparallel with the diaphragm. The rear wall, 2, is proyided with theusual aperture 6 to communicate with the collar or fitting, T, proyidedwith a lateral flange, 8, which is secured to the body of the sound box,the said collar, 7, being adapted to be connected to the portion of thephonograph or other instrmnentleading to the amplifying horn o1mechanism in the usual manner, and being preferably provided with theusual locking stud, 9.

1 prefer to form the collar, 7, with its flange, 8, of baltelite dilectoalthough it may be formed of metal or other material if desired. I alsoprefer to introduce a washer, 10, between the flange, 8, of the collarand the rear wall of the sound box, and to provide another washer, 11,surrounding the collar, 7, on the exterior face of the flange, 8, and toproride a clamping ring, 12, engaging the last mentioned washer, theclamping ring being connected to the sound box by suitable connectionsas the screws, 13, pass ing through apertures in the washers, 10, and11. and the flange, 8, of the collar to secure the parts together inproper relation to the sound box. Jl'ho washers, l and 11, may be ofrubber or I may employ bahelite dilecto for this purpose also, and theclamping ring, 12, is prefe ably of balrelite dilecto or othernon-metallic material, although in some instances I may employ a. metalclamping ring in which case I prefer to make the inner diameter of thering of such a size that it will not come in contact with the collar. 7,as shown.

1 represents the diaphragm which is preferably non-metallic andpreferably formed of mica. the outer edges of the diaphragm beingsupported by the usual cushion rings, 10 and 1?. held in place by theretaining ring, 5, which is connected to the body of the sound box bythe screws, 1 f, or otherwise. The diaphragm is proyided with theclariihingr disk, 20. which is formed of a thin sheet of balielitedilecto with the fibrous material 21 thereof lying in planes parallel tothe plane of the diaphragm, and cemented to the diaphragm throughout thecontacting surfaces thereof by a cement which is not a l'l'ected byheat, cold or moisture or other atmospheric cmulitions, which is alsotrue of the clarifying disk itself.

In the drawing 1 have shown the claritying disk as extending over thecentral portion of the diaphragm only and located conce tricallytherewith. It is to be understood that it may extend a greater ordistance from the center to the periphe of the diaphragm according tothe conoitions under which it is to be used, and in some instances maybe co-extensire with the diaphragm although prefer to have it of lessdiameter than the diaphragm. its a matter of experienc I have found thatthe size of the disl: which giyes the est results varies somewhat withthe size and character of the amplifying horn or other amplifyingmechanism. employed in the in trmnent with which the srund box is used,a compaia tiyely small disk gi ing good results with a large horn andrice yersa.

The stylus arm, is of the usual or an}- preferred form, the upper endhaving a shoulder portion and a threaded portion of similar diameterextending through a central aperture in the clarifying disk, and throughthe diaphragm and being secured in position by a nut in the usualmanner. a minute quantity of wax being applied around the nut, and thestem of the styhis arm on the inner face of the diaphragm, and on theexterior face of the disk in the usual manner as shown. The stylus armis provided with a pivot engaging portion, 26, which is preferablyengaged by two pivot screws. 27, extending through ears. and providedwith set nuts, 29, although other forms of mountings or the stylus armmay by substituted for those herein shown and described.

In Figs. 1 and i l ha e shown the ears. which are preferably formed ofnon metallic material. for example baltelite dilecto. made integral withor s cured to the retaining ring. 5, so as to avoid the possibility ofany metallic resonance from the pivotal connection of the styli'is arm.In some instances 1 may form a notch or re cess in the retaining ring,5, as shown in Fig. and provide a mounting, 30, having ears, 28", formedthereon. said mounting being directly connected to the non-metallicbody, 1, of the sound box so as to transfer the support for the stylusarm from the retaining ring to the body of the sound box as shown insaid figure. In such case the mounting might be made of metal although Iprefer that it should be of nonunetallic material.

In Fig. l I have shown another slight modification in which the bodyhere indicated at 1 of the sound box is provided with a recess or notchin which is located a block, 31, preferably of non-metallic material,and prefer ably of bakelite dilecto, provided wlth the ears, 28 saidblock fitting in said notch and extending through a corresponding recessin the retaining ring and being secured to the body of the sound box byscrews, 32. In all of these constructions it will be noted that therecan be no metallic vibration at the point of pivoting to communicateitself to the diaphragm through the stylus arm or through thenon-metallic body of the sound box. The stylus arm is provided with theusual needle recess and clamping screw 35, a needle being shown inposition at, 36.

In the use of my improved sound box it will be found that the clarifyingdisk of bakelite dilecto modifies the delicately responsive non-metallicmica diaphragm to which it is so intimately connected, in such manner asto eliminate all metallic Sounds and prevent the blending or mufiling oftones, all the tones as well as the most minute over-tones beingrendered with perfeet clarity and distinctness and resulting in theperfect versimilitude of the human voice or voices or musical instrumentor instruments the tones of which are reproduced. The non-metallic bodyof the sound box, also preferably of bakelite dilecto, and the mount ingof tie stylus arm directly thereupon preferably without the interventionof any direct metallic contact in the manner described also coeperateswith the clarifying disk in more perfectly eliminating the me tallicresonance and clarifying the tone reproduced.

I attribute the results obtained by my improved sound box to the use ofthe clarifying disk and body composed of quasi-vitreous materialcombined with fibrous material, the best form of which I consider to bebakelite dilecto. By the term quasi-vitreous I mean a material likebakelite which is hard, glasslike and of uniform density, while at thesame time it is tough and not so brittle as glass, and is not under anyinternal or external stress, as truly vitreous material is apt to be.This peculiarity in combination with the fibrous material causes aresultant material which possesses the desired quality of resonancetogether with the requisite flexibility and at the same time isincapable of warping and is not affected by atmospheric conditions ofany kind. The clarifyink disk of bakelite dilecto on account of itspeculiar qualities also cooperates with the non-metallic mica disk inpreventing the splintering or separation of the almost infinitesimallythin strata along their planes of cleavage of the mica at and adjacentto the center of the diaphragm where the stylus arm is connected, andthus prevents the deterioration of the mica diaphragm which otherwise isextremely likely to result with continued use.

In the practical use of sound boxes in which my improved clarifying diskis used, I find that a greater volume of sound is obtained with asmaller or lighter needle than is possible with other forms of soundboxes and this in itself is a desirable feature of my invention as itmaterially lessens the wear on the grooves of the records.

The beneficial results obtained by my improved clarifying disk hereindescribed are also obtained in a considerable degree in connection withmetallic diaphragms or diaphragms having metallic portions such as areused for example in telephonic apparatus. In connection with thesediaphragms also the provision of the concentric clarifying disk resultsin eliminating muddy and confused tones and rendering the reproductionclear, and in which the metallic resonance is greatly reduced.

By the term bakelite as used in the foregoing specification and in thefollowing claims I mean a phenolic condensation prodnot formed bycombining a phenolic body with formaldehyde, which isbest known by oneof its trade names bakelite.

My improved sound reproducing box is not specifically claimed herein asit forms the subject matter of a separate application for Letters Patentof the United States filed by me on or about June 2, 1916, and givenSerial No. 101,252, the same being a division of this application.

IV hat I claim and desire to secure by Letters Patent is:

1. In a sound reproducing apparatus, the combination with a diaphragm ofa concentric clarifying disk of a phenolic condensation product havingembodied therein strata of fibrous material, parallel with the diaphram, the said disk being adhesively secured to the diaphragm throughouttheir adjacent surfaces.

2. In a sound reproducing apparatus, the combination with a diaphragm ofa concentric clarifying disk composed of bakelite having embodiedtherein strata of fibrous material parallel with the diaphragm, saiddisk being cemented to the diaphragm throughout their adjacent surfaces.

3. In a sound reproducing apparatus, the combination with a diaphragm ofa concentric clarifying disk composed of bakelite dilecto cemented tothe diaphragm throughout their adjacent surfaces.

In testimony whereof I afiix my signature.

JOHN A. STEUBER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

